package hihocoder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;

/**
 * 
 */

/**
 * @author zhongfang
 *
 */
public class 一人麻将 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		int n=scanner.nextInt();
		scanner.nextLine();
		HashMap<HashMap<Character, Integer>, Integer> map=new HashMap<>(14+n);
		String string=scanner.nextLine();
		String[] strings=string.split(" ");
		for (int i = 0; i < strings.length; i++) {
			char c=strings[i].charAt(0);
			Integer in=Integer.parseInt(string, strings[i].charAt(1));
			if(map.keySet().contains(c)&&((HashMap)map.keySet()).get(c).equals(i)){
				
			}
		}
	}

}
